1. Field of the Invention
The present invention relates generally to the support and release of a graphic arts die plate on an assembly for use in a press. More specifically, the present invention concerns a die assembly wherein a die plate is carried by a magnetic chase and held in position thereon through magnetic securement by a series of magnets embedded in the chase. The assembly has particular utility for use in flatbed graphic arts presses to be used for hot foil stamping, die cutting, or embossing. In a preferred embodiment, the magnetic chase is substituted for a conventional apertured chase of a press. A selectively actuatable releasing assembly is employed to elevate the die plate to a magnetically disengaged position above the magnetic chase to facilitate alignment of the die plate with images on a substrate to be processed in the press.
2. Discussion of the Prior Art
Those of ordinary skill in the art will appreciate that it has long been the practice, where multiple hot foil stamping, die cutting, and/or embossing dies are to be mounted on an apertured flat chase, to secure each die to the chase using a plurality of toggle connectors. Traditionally, each toggle is inserted into an aperture of the chase adjacent the perimeter of a corresponding die. Sufficient toggles are provided for each die to assure a secure fixation of that die to the chase. It is not uncommon to have as many as ten to twenty or more dies arranged on a single chase, depending on the number of images to be hot foil stamped, die cut, or embossed. An apertured chase for multiple image applications can commonly have a size of forty by twenty-seven inches, or be even larger.
Conventionally, each die is positioned on the apertured chase in approximate registration with a respective substrate image to be hot foil stamped, die cut, or embossed. After all of the dies are secured to the chase with toggles, the chase (with the engraving dies mounted thereon) is “run in” against the image-bearing substrate to ascertain whether the dies are in fact properly aligned with respective images. Most usually, some further adjustment of the individual dies is required to obtain the necessary registration. This hit-or-miss procedure is repeated until all of the dies are each finally registered with their images. Even experienced graphic arts press operators will normally need at least three to eight hours of time to mount a number of dies on an apertured support chase using individual toggles and to align and realign all of the dies until they are in final register with the substrate images.
U.S. Pat. No. 7,096,709 (“the '709 patent”), hereby incorporated by reference in its entirety, to the extent not inconsistent with the present disclosure, discloses a graphic arts die and die carrier plate assembly that is adapted to be mounted as a unit on an apertured chase of a flatbed graphic arts press. The assembly of the '709 patent has particular utility for hot foil stamping, die cutting, and substrate embossing applications, or combinations thereof. Each of the dies of the assembly is fixedly mounted in predetermined relative relationship on a flat, metal die carrier plate. Fasteners for each die are pre-attached to the die carrier plate in disposition such that when respective dies are secured to the plate, the die images all align with one another and, if applicable, with respect to artwork on a substrate.
Thus, those of ordinary skill in the art will appreciate that using the graphic arts die and die carrier plate assembly of the '709 patent, commercialized by, or under the auspices of, Universal Engraving, Inc. of Overland Park, Kans. (the assignee of record of the '709 patent and the present application) as its UniLock-Up system, a large number of individual dies may all be mounted in predetermined, preregistered relationship on a die carrier plate that is then secured to a conventional apertured chase. Significant time is saved using the UniLock-Up system as compared with prior conventional methods because only about an hour is required to align and attach all of the dies to the die carrier plate. To this end, the fasteners for the dies are secured to the die carrier plate in predetermined disposition based on the locations of respective substrate artwork images.
As explained in greater detail in the disclosure of the '709 patent, each of the individual dies may be shifted to a minor extent to obtain necessary registration with respective substrate images. Such minor adjustment, though, requires only loosening of threaded members, such as screws or threaded nuts, followed by re-tightening of the screws or threaded nuts after the die has been shifted, rather than loosening and tightening of toggles, or even in some instances re-positioning of the toggles. One important advantage of preregistration of the dies on the die carrier plate is the fact that such plate, with the dies thereon, may be stored for use at later times without the necessity of once again registering the dies as has conventionally been necessary.